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Does chocolate reduce blood pressure? A meta-analysis.

ABSTRACT: Dark chocolate and flavanol-rich cocoa products have attracted interest as an alternative treatment option for hypertension, a known risk factor for cardiovascular disease. Previous meta-analyses concluded that cocoa-rich foods may reduce blood pressure. Recently, several additional trials have been conducted with conflicting results. Our study summarises current evidence on the effect of flavanol-rich cocoa products on blood pressure in hypertensive and normotensive individuals.We searched Medline, Cochrane and international trial registries between 1955 and 2009 for randomised controlled trials investigating the effect of cocoa as food or drink compared with placebo on systolic and diastolic blood pressure (SBP/DBP) for a minimum duration of 2 weeks. We conducted random effects meta-analysis of all studies fitting the inclusion criteria, as well as subgroup analysis by baseline blood pressure (hypertensive/normotensive). Meta-regression analysis explored the association between type of treatment, dosage, duration or baseline blood pressure and blood pressure outcome. Statistical significance was set at P < 0.05.Fifteen trial arms of 13 assessed studies met the inclusion criteria. Pooled meta-analysis of all trials revealed a significant blood pressure-reducing effect of cocoa-chocolate compared with control (mean BP change +/- SE: SBP: -3.2 +/- 1.9 mmHg, P = 0.001; DBP: -2.0 +/- 1.3 mmHg, P = 0.003). However, subgroup meta-analysis was significant only for the hypertensive or prehypertensive subgroups (SBP: -5.0 +/- 3.0 mmHg; P = 0.0009; DBP: -2.7 +/- 2.2 mm Hg, P = 0.01), while BP was not significantly reduced in the normotensive subgroups (SBP: -1.6 +/- 2.3 mmHg, P = 0.17; DBP: -1.3 +/- 1.6 mmHg, P = 0.12). Nine trials used chocolate containing 50% to 70% cocoa compared with white chocolate or other cocoa-free controls, while six trials compared high- with low-flavanol cocoa products. Daily flavanol dosages ranged from 30 mg to 1000 mg in the active treatment groups, and interventions ran for 2 to 18 weeks. Meta-regression analysis found study design and type of control to be borderline significant but possibly indirect predictors for blood pressure outcome.Our meta-analysis suggests that dark chocolate is superior to placebo in reducing systolic hypertension or diastolic prehypertension. Flavanol-rich chocolate did not significantly reduce mean blood pressure below 140 mmHg systolic or 80 mmHg diastolic.

SUBMITTER: Ried K

PROVIDER: S-EPMC2908554 | biostudies-other | 2010 Jun

REPOSITORIES: biostudies-other

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Does chocolate reduce blood pressure? A meta-analysis.

Ried Karin K Sullivan Thomas T Fakler Peter P Frank Oliver R OR Stocks Nigel P NP

BMC medicine 20100628

<h4>Background</h4>Dark chocolate and flavanol-rich cocoa products have attracted interest as an alternative treatment option for hypertension, a known risk factor for cardiovascular disease. Previous meta-analyses concluded that cocoa-rich foods may reduce blood pressure. Recently, several additional trials have been conducted with conflicting results. Our study summarises current evidence on the effect of flavanol-rich cocoa products on blood pressure in hypertensive and normotensive individua ...[more]

PMID: 20584271

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Project description:IntroductionThe impact of reduction of systolic blood pressure or body weight on reduction of cardiovascular events during the treatment with glucagon-like peptide 1 receptor agonists (GLP-1RAs) or sodium-glucose cotransporter 2 inhibitors (SGLT2is) for type 2 diabetes is unclear.MethodsWe searched Embase and PubMed. We performed meta-analysis using hazard ratio (HR) and 95% confidence interval (CI) as effect size stratified by drug class on six endpoints of interest, which were major adverse cardiovascular events (MACE), hospitalization for heart failure (HHF), cardiovascular death (CVD), myocardial infarction (MI), stroke, and all-cause death (ACD). We performed meta-regression to assess the difference between GLP-1RAs and SGLT2is, and the impact of reduction of systolic blood pressure or body weight on reduction of cardiovascular events.ResultsWe included 11 randomized trials. Compared with placebo, SGLT2is reduced HHF by 32% (HR 0.68, 95% CI 0.60-0.76) whereas GLP-1RAs reduced HHF by only 9% (HR 0.91, 95% CI 0.83-0.99). The benefit from SGLT2is on HHF was significantly greater than that from GLP-1RAs (Psubgroup = 0.004). GLP-1RAs reduced stroke by 16% (HR 0.84, 95% CI 0.76-0.93) whereas SGLT2is did not reduce stroke (HR 0.96, 95% CI 0.82-1.12). GLP-1RAs and SGLT2is similarly reduced MACE by 12%, CVD by 15%, MI by 9%, and ACD by 13%. The effects of systolic blood pressure reduction and body weight reduction on the logarithms of HRs of GLP-1RAs or SGLT2is vs. placebo as for reducing six endpoints of interest were not statistically significant (β ranged from - 0.145 to 0.269, and P ranged from 0.211 to 0.941).ConclusionsGLP-1RAs and SGLT2is lead to similar benefits on MACE, CVD, MI, and ACD in adults with type 2 diabetes. The benefit from SGLT2is on HHF is greater than that from GLP-1RAs, while GLP-1RAs vs. placebo significantly reduce stroke whereas SGLT2is do not. The two drug classes reduce cardiovascular events independent of reductions of systolic blood pressure and body weight.

Project description:ObjectiveTo evaluate the association of chocolate consumption with the risk of developing cardiometabolic disorders.DesignSystematic review and meta-analysis of randomised controlled trials and observational studies.Data sourcesMedline, Embase, Cochrane Library, PubMed, CINAHL, IPA, Web of Science, Scopus, Pascal, reference lists of relevant studies to October 2010, and email contact with authors.Study selectionRandomised trials and cohort, case-control, and cross sectional studies carried out in human adults, in which the association between chocolate consumption and the risk of outcomes related to cardiometabolic disorders were reported.Data extractionData were extracted by two independent investigators, and a consensus was reached with the involvement of a third. The primary outcome was cardiometabolic disorders, including cardiovascular disease (coronary heart disease and stroke), diabetes, and metabolic syndrome. A meta-analysis assessed the risk of developing cardiometabolic disorders by comparing the highest and lowest level of chocolate consumption.ResultsFrom 4576 references seven studies met the inclusion criteria (including 114,009 participants). None of the studies was a randomised trial, six were cohort studies, and one a cross sectional study. Large variation was observed between these seven studies for measurement of chocolate consumption, methods, and outcomes evaluated. Five of the seven studies reported a beneficial association between higher levels of chocolate consumption and the risk of cardiometabolic disorders. The highest levels of chocolate consumption were associated with a 37% reduction in cardiovascular disease (relative risk 0.63 (95% confidence interval 0.44 to 0.90)) and a 29% reduction in stroke compared with the lowest levels.ConclusionsBased on observational evidence, levels of chocolate consumption seem to be associated with a substantial reduction in the risk of cardiometabolic disorders. Further experimental studies are required to confirm a potentially beneficial effect of chocolate consumption.

Project description:BackgroundThe Global Burden of Diseases Study 2010 reported that hypertension is worldwide the leading risk factor for cardiovascular disease, causing 9.4 million deaths annually. We examined to what extent self-measurement of home blood pressure (HBP) refines risk stratification across increasing categories of conventional blood pressure (CBP).Methods and findingsThis meta-analysis included 5,008 individuals randomly recruited from five populations (56.6% women; mean age, 57.1 y). All were not treated with antihypertensive drugs. In multivariable analyses, hazard ratios (HRs) associated with 10-mm Hg increases in systolic HBP were computed across CBP categories, using the following systolic/diastolic CBP thresholds (in mm Hg): optimal, <120/<80; normal, 120-129/80-84; high-normal, 130-139/85-89; mild hypertension, 140-159/90-99; and severe hypertension, ?160/?100. Over 8.3 y, 522 participants died, and 414, 225, and 194 had cardiovascular, cardiac, and cerebrovascular events, respectively. In participants with optimal or normal CBP, HRs for a composite cardiovascular end point associated with a 10-mm Hg higher systolic HBP were 1.28 (1.01-1.62) and 1.22 (1.00-1.49), respectively. At high-normal CBP and in mild hypertension, the HRs were 1.24 (1.03-1.49) and 1.20 (1.06-1.37), respectively, for all cardiovascular events and 1.33 (1.07-1.65) and 1.30 (1.09-1.56), respectively, for stroke. In severe hypertension, the HRs were not significant (p?0.20). Among people with optimal, normal, and high-normal CBP, 67 (5.0%), 187 (18.4%), and 315 (30.3%), respectively, had masked hypertension (HBP?130 mm Hg systolic or ?85 mm Hg diastolic). Compared to true optimal CBP, masked hypertension was associated with a 2.3-fold (1.5-3.5) higher cardiovascular risk. A limitation was few data from low- and middle-income countries.ConclusionsHBP substantially refines risk stratification at CBP levels assumed to carry no or only mildly increased risk, in particular in the presence of masked hypertension. Randomized trials could help determine the best use of CBP vs. HBP in guiding BP management. Our study identified a novel indication for HBP, which, in view of its low cost and the increased availability of electronic communication, might be globally applicable, even in remote areas or in low-resource settings.

Project description:BACKGROUND:Clinical practice guidelines have traditionally recommended blood pressure treatment based primarily on blood pressure thresholds. In contrast, using predicted cardiovascular risk has been advocated as a more effective strategy to guide treatment decisions for cardiovascular disease (CVD) prevention. We aimed to compare outcomes from a blood pressure-lowering treatment strategy based on predicted cardiovascular risk with one based on systolic blood pressure (SBP) level. METHODS AND FINDINGS:We used individual participant data from the Blood Pressure Lowering Treatment Trialists' Collaboration (BPLTTC) from 1995 to 2013. Trials randomly assigned participants to either blood pressure-lowering drugs versus placebo or more intensive versus less intensive blood pressure-lowering regimens. We estimated 5-y risk of CVD events using a multivariable Weibull model previously developed in this dataset. We compared the two strategies at specific SBP thresholds and across the spectrum of risk and blood pressure levels studied in BPLTTC trials. The primary outcome was number of CVD events avoided per persons treated. We included data from 11 trials (47,872 participants). During a median of 4.0 y of follow-up, 3,566 participants (7.5%) experienced a major cardiovascular event. Areas under the curve comparing the two treatment strategies throughout the range of possible thresholds for CVD risk and SBP demonstrated that, on average, a greater number of CVD events would be avoided for a given number of persons treated with the CVD risk strategy compared with the SBP strategy (area under the curve 0.71 [95% confidence interval (CI) 0.70-0.72] for the CVD risk strategy versus 0.54 [95% CI 0.53-0.55] for the SBP strategy). Compared with treating everyone with SBP ? 150 mmHg, a CVD risk strategy would require treatment of 29% (95% CI 26%-31%) fewer persons to prevent the same number of events or would prevent 16% (95% CI 14%-18%) more events for the same number of persons treated. Compared with treating everyone with SBP ? 140 mmHg, a CVD risk strategy would require treatment of 3.8% (95% CI 12.5% fewer to 7.2% more) fewer persons to prevent the same number of events or would prevent 3.1% (95% CI 1.5%-5.0%) more events for the same number of persons treated, although the former estimate was not statistically significant. In subgroup analyses, the CVD risk strategy did not appear to be more beneficial than the SBP strategy in patients with diabetes mellitus or established CVD. CONCLUSIONS:A blood pressure-lowering treatment strategy based on predicted cardiovascular risk is more effective than one based on blood pressure levels alone across a range of thresholds. These results support using cardiovascular risk assessment to guide blood pressure treatment decision-making in moderate- to high-risk individuals, particularly for primary prevention.

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Does chocolate reduce blood pressure? A meta-analysis.

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Does chocolate reduce blood pressure? A meta-analysis.

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